What is stress?

Whether it's a short-term frustration like a traffic jam or a major life event like divorce or job loss, psychological stress can affect our bodies.

Stress can be highly personal, with one person's unpleasant experience another's exhilarating adventure. And a little bit of stress is thought to be good for memory and motivation. However, about 70% of doctor visits and 80% of serious illnesses may be exacerbated or linked to stress.

Here are 25 ways that stress can affect the body. The good news is that there is much you can do—exercise, meditation, and more—to reduce the impact of stress in your life.

What is stress?

Whether it's a short-term frustration like a traffic jam or a major life event like divorce or job loss, psychological stress can affect our bodies.

Stress can be highly personal, with one person's unpleasant experience another's exhilarating adventure. And a little bit of stress is thought to be good for memory and motivation. However, about 70% of doctor visits and 80% of serious illnesses may be exacerbated or linked to stress.

Here are 25 ways that stress can affect the body. The good news is that there is much you can do—exercise, meditation, and more—to reduce the impact of stress in your life.

Fight or flight

The stress response has evolved over a millennium to protect you from danger. Also known as the flight-or-fight response, it gets the body ready for action. So if you're in danger, the brain's hypothalamus sends triggersboth chemical and along the nervesto the adrenals, which are glands that sit on top of each kidney like a hat perched on a head.

The adrenals then churn out hormones, such as cortisol, which raise blood pressure and blood sugar (among other things). This is dandy if you need to outrun a hungry lion, less so if the perceived threat is a looming layoff. And it can be harmful to health if sustained over time.

Cravings

Studies have linked cortisol, a hormone released during times of stress, to cravings for sugar and fat.

Scientists believe the hormone binds to receptors in the brain that control food intake. And if you already have a high body mass index, you may be even more susceptible.

The key is to know your triggers, and be ready when deadlines loom (or whenever stress is likely). That means, stock up on healthy snacks if you tend to hit the vending machine at work, or make sure you don't unhealthy treats on hand for those times when an attack of emotional eating is likely.

Fat storage

Part of that link is due to poor eating during stress, but the stress hormone cortisol may also increase the amount of fat tissue your body hangs onto and enlarge the size of fat cells. Higher levels of cortisol have been linked to more deep-abdominal fatyes, belly fat.

Heart

The exact relationship between stress and heart attack is still unclear, but evidence is mounting that there is one. A recent study of 200,000 employees in Europe found that people who have stressful jobs and little decision-making power at work are 23% more likely to have a first heart attack than people with less job-related stress.

The best thing to do is lead a heart-healthy lifestyle and focus on reducing stress in your life. Here are 12 steps you can take to help your heart by combatting stress.

Headaches

"Fight or flight" chemicals like adrenaline (epinephrine) and cortisol can cause vascular changes that leave you with a tension headache or migraine, either during the stress or in the "let-down" period afterwards.

Memory

Too much of the stress hormone cortisol can interfere with the brain's ability to form new memories.

During acute stress, the hormone also interferes with neurotransmitters, the chemicals that brain cells use to communicate with each other. That can make it hard to think straight or retrieve memories.

Pregnancy

The normal stresses of everyday life are unlikely to affect a pregnancy, but severe stress, like losing a job or going through a divorce, can increase the chances of premature labor. There’s even some research suggesting that very high levels of stress can affect the developing fetal brain. Prenatal yoga and other stress-reduction techniques can help, so talk to your doctor if you're severely stressed and pregnant.

Stress may even affect the ability to get pregnant in the first place. One study found that women with the highest levels of a stress-related substance called alpha-amylase were about 12% less likely to get pregnant each cycle than those with the lowest concentrations.

Blood sugar

Stress is known to raise blood sugar, and if you already have type 2 diabetes you may find that your blood sugar is higher when you are under stress.

Changing what you eat, exercising more, or adjusting medication can help to keep it under control.

One study of obese black women without diabetes found that those who produced more stress-related epinephrine when asked to recall stressful life events had higher fasting glucose and bigger blood sugar spikes than those with lower epinephrine, suggesting it might raise your risk for getting diabetes too.

Digestion

Heartburn, stomach cramping, and diarrhea can all be caused by or worsened by stress.

In particular, irritable bowel syndrome, or IBS, which is characterized by pain and bouts of constipation and diarrhea is thought to be fueled in part by stress. However, stomach ulcers, once thought to be caused by stress, are triggered by H. pylori bacteria, which can be treated with antibiotics.

Blood pressure

A stressful situation can raise your blood pressure temporarily by constricting your blood vessels and speeding up your heart rate, but these effects disappear when the stress has passed.

It's not yet clear whether chronic stress can cause more permanent changes in your blood pressure, but techniques like mindfulness and meditation may help, according to Dr. Hagen. In addition, there are many natural ways to reduce blood pressure, including diet and exercise.

Skin

Most acne sufferers already suspect this is true, and they seem to be right: Stress can give you zits. Research suggests that students with acne are more prone to outbreaks during exams compared to less stressful time periods. An increase of male hormones known as androgens could be a culprit, particularly in women.

Stress can also trigger psoriasis to appear for the first time or make an existing case more severe. Many doctors are starting to incorporate stress-management techniques such as biofeedback and meditation into their treatment programs for the skin disease.

Back pain

Stress can set off an acute attack of back pain as well as contribute to ongoing chronic pain, probably for the simple reason that the "fight or flight" response involves tensing your muscles so that you're ready to spring into action.

One recent study in Europe found that people who are prone to anxiety and negative thinking are more likely to develop back pain, while a U.S. study tied anger and mental distress to ongoing back pain.

Colds

People exposed to common cold viruses are less likely to fight off the germs successfully if they have ongoing psychological stress in their lives.

Researchers believe stressed people's immune cells may be less sensitive to a hormone that turns off inflammation, which could offer a clue to why stress can be correlated with more serious diseases as well.

Asthma

Stress seems to exacerbate asthma in people who have the lung condition.

In one study, children who experienced severe stress such as the death of a loved one had a nearly two-fold increase in the risk of an asthma attack over the following two weeks compared to those not under stress.

Researchers aren't sure why, but stress may amplify the immune response to asthma triggers such as pollen, animal dander, or dust.

Job performance

Studies of employees ranging from military personnel to bankers show that stress reduces productivity and satisfaction at work, and is linked to depression too.

One solution is to ask your employer to offer stress-management training, which can address company-wide stressors like weak communication channels as well as focusing on stress busters for individuals.

"Stress clearly has an effect on productivity, and the costs of that for employers can be very high," Dr. Hagen points out.

Seizures

Although it's not all that common, doctors at the John Hopkins Hospital have found that some people who are especially sensitive to stress can experience seizure-like symptoms, such as far-off staring and convulsions.

Up to one-third of people treated for seizures at the hospital didn't respond to standard anti-seizure medication and doctors concluded that they had stress-induced symptoms.

Known as conversion disorder, some people can subconsciously express emotional trauma as physical symptoms, they say.